A rolling-element bearing cage of the above-mentioned type or such a rolling-element bearing cage-element is known from JP 2007 100 909 A. The rolling-element bearing cage element disclosed here includes a number of lubrication channels, via which the lubricant can reach into the contact surfaces to the rolling elements. JP 2003 206 932 A1, DE 10 2008 049 036 A1, JP 2008 261 478 A, DE 10 2006 001 593 B3, JP 2000 291 668 A, U.S. Pat. No. 8,523,451 B2, DE 10 2008 059 571 A1, and JP 2005 054 836 A show similar and other solutions.
The guiding of rolling elements—whether designed as rollers or balls—in a rolling-element bearing using cages is well known. The cages here can be classically configured, i.e., include two side rings between which bridges extend. They can also be cage segments that are placed between two rolling elements, which cage segments, however, are not connected via side rings.
In this context it is important to supply sufficient lubricant to the rolling elements for their rolling contact.
It is known in this regard that primarily only the lubricant in the vicinity of the cage pockets is usable for active bearing lubrication. To date the rolling contact surface between the cage bridge and the rolling element is provided with a large osculation diameter of the contact surface on the bridge so that lubricant can come into direct rolling contact. However, since the gap thereby arising between cage bridge and rolling element can only be embodied to a very limited degree so that the cage bridge maintains its guiding property, also only a very limited amount of lubricant can be held in rolling contact.
To date the problem of insufficient lubrication in the rolling contact between the cage bridge and the rolling element has been addressed by providing the rolling-contact surface on the cage bridge with an osculation diameter that is larger than the diameter of the rolling element. The lubricant can flow into the gap thus arising between the rolling-contact surface on the cage bridge and the rolling element. Disadvantageously, a relatively frequent relubrication of the bearing is required in order to maintain its function or avoid wear, since the receiving capacity for lubricating grease is relatively low.